The field of the invention relates generally to energy harvesting systems and, more particularly, to energy harvesting systems that convert waste heat to power using a bladeless turbine or a boundary layer turbine.
Waste heat is generated from machines, electrical equipment and industrial processes for which there exists no useful application and is often regarded as a waste by-product. For example, waste heat can be generated from steel mills, concrete plants, smokestacks, and automobile exhausts. Moreover, waste heat can be harvested for power. At least some known systems that harvest waste heat for power use steam turbine engines to convert heat to power by extracting thermal energy from pressurized steam prior to converting the energy into rotary motion used to drive a generator. Known generators convert the mechanical energy into electrical power.
However, the process of converting thermal energy into electrical power via such systems is generally inefficient. Specifically, to generate a large amount of power from thermal energy, a relatively high temperature heat is required. Although, heat losses in such a process contribute greatly to the overall efficiency of the system, the high temperatures are necessary to ensure operation of the system. For example, in at least some known steam turbine engines, the turbines are not operable with liquid flow as liquid may damage the turbine and lead to erosion of the components of the turbine. As such, known energy harvesting systems require additional heating technology, such as superheaters, to ensure any fluid flow is vaporized to steam prior to any flow entering the turbine. Therefore, the cost effectiveness and/or operational efficiency of known energy harvesting systems may be limited.